{big babble} At What Point do You Check on Other Peoples’ Kids?

If we’ve made it this far into parenting we’ve all had other peoples’ kids at our house. And chances are those kids have done something out of the ordinary, gross or strange. I know my kid is guilty of several things under the watchful eyes of another, including losing a tooth and getting pinkeye. But my question is mostly about kids of another gender, in my case boys. I don’t have boys. I didn’t grow up with boys. I don’t get boys.